The speaker is the mountain. Its state of mind is revealed as it experiences and responds to different times of day. Its mindset is also revealed by the anxious and alienated words and images it uses, as well as its repeated, unanswered question about how old it is.

Literary devices include personification, for the mountain is treated as if it is a living human being, with thoughts and emotions. Other literary devices include similes, which are comparisons that use the words like or as. For example, the mountain says that

the valleys stuff
impenetrable mists
like cotton in my ears.

In this simile, the mountain is likening itself to a person who cannot hear. The simile is also an example of imagery, which is description using any of the fives sense of sight, sound, taste, touch, or smell. We can imagine how the mists seem to envelope the mountain and plug up its ears.

Bishop also uses a simile when she writes,

The deepest demarcation
can slowly spread and sink
like any blurred tattoo.

Bishop plays with cliches, such as by having the mountain say the morning is like an "open book," a term for something that is completely obvious, only to reveal it is "too close to read in comfort," changing the cliche's meaning into something anxious.

Bishop plays on cliches again when she writes, expressing the mountain's irritation,

Let the moon go hang [itself],
the stars go fly their kites.

Imagery also shows the passage of time the mountain has experienced. In the quote below, fallen feathers have fossilized into layers:

Stone wings have sifted here
with feathers hardening feathers.

We hear alliteration in the s, h, and f sounds in the verse above.

The mountain uses imagery we associate with old age, such as deafness and drooling:

I am growing deaf. Bird-calls
dribble and the waterfalls
go unwiped.

Bishop employs repetition in the alternating final lines of each quatrain to create a sense of rhythm and regularity. The quatrains, more or less written in iambic tetrameter—except for the last line of each stanza, which is in trimeter—help establish a sense of structure and regularity.

The tone is one of anxiety as the mountain repeatedly expresses its desire to know how old it is, a desire that is left unanswered. The mountain uses the word "blench," which means to flinch, as well as "staggeringly" to show its anxiety about not knowing it age. The mountain feels isolated, alienated, and confused beneath a seemingly assured, timeless surface.